But these are symptoms. The Dark Tower was because of Vic, no? Maybe Bradley too, but mostly Vic. Vic was a virus against which Google had no immunity. "Do it my way or your career is over". Well, his direction sucked, and that's what you get when you give full trust and power to the wrong individual.
The engineering headcount was ridiculous for Google+. It was also ridiculous to have OKRs for every team at Google to integrate with Google+. Facebook (or really any company) didn't start with Mark Zuckerberg hiring a 1000 engineers and start cranking. If a VC cut him a check for $500 million after his MVP Facebook would probably be a failure. Instead he built the MVP with a few engineers and increased headcount as he increased the user base and shifted vision. Google had this mistaken notion that they could just throw more engineers at the problem and skip the whole product discovery process.